Managing Hierarchical Data in MySQL

Managing Hierarchical Data in MySQL

http://dev.mysql.com/tech-resources/articles/hierarchical-data.html

Most users at one time or another have dealt with hierarchical data in a SQL database and no doubt learned that the management of hierarchical data is not what a relational database is intended for. The tables of a relational database are not hierarchical (like XML), but are simply a flat list. Hierarchical data has a parent-child relationship that is not naturally represented in a relational database table.